We use cookies to understand how you use our site and to improve your experience. This includes personalizing content and advertising. To learn more, click here. By continuing to use our site, you accept our use of cookies. Cookie Policy.

Features Partner Sites Information LinkXpress
Sign In
Advertise with Us
Technopath Clinical Diagnostics - An LGC Company

Download Mobile App




Events

ATTENTION: Due to the COVID-19 PANDEMIC, many events are being rescheduled for a later date, converted into virtual venues, or altogether cancelled. Please check with the event organizer or website prior to planning for any forthcoming event.
06 Feb 2023 - 09 Feb 2023

Blood Test to Separate Bacterial and Viral Infections Could Reduce Antibiotic Overuse

By LabMedica International staff writers
Posted on 26 Dec 2022
Print article
Image: New blood test to identify infections could reduce global antibiotic overuse (Photo courtesy of Pexels)
Image: New blood test to identify infections could reduce global antibiotic overuse (Photo courtesy of Pexels)

In developing countries, most antibiotic prescriptions are not only pointless - an estimated 70% to 80% of them are given for viral infections, which the medications don’t treat - they’re also harmful, as overuse of antibiotics accelerates antibiotic resistance. A similar problem exists in the U.S., where an estimated 30% to 50% of antibiotic prescriptions are given for viral infections. Existing methods to diagnose whether a patient has a bacterial or viral infection include growing the pathogen in a petri dish, which takes several days, or polymerase chain reaction (PCR) testing, which requires knowing the specific pathogen to look for. Now, a new gene expression-based test could allow doctors around the world to quickly and accurately distinguish between bacterial and viral infections, thereby cutting down on antibiotic overuse.

The test developed by scientists at Stanford Medicine (Stanford, CA, USA) is based on how the patient’s immune system responds to an infection. It is the first such diagnostic test validated in diverse global populations - accounting for a wider range of bacterial infections - and the only one to meet the accuracy targets set by the World Health Organization and the Foundation for Innovative New Diagnostics to address antibiotic resistance. Those targets include at least 90% sensitivity (correctly identifying true positives) and 80% specificity (correctly identifying true negatives) to distinguish bacterial and viral infections. The test is one of a new crop of diagnostic tests that look at the host response - that is, how the patient’s immune system is reacting - to identify the type of infection. They measure the expression of certain genes involved in the host’s immune response.

Current host-response tests can distinguish extracellular bacterial infections from viral infections with more than 80% accuracy, but they can identify only 40% to 70% of intracellular infections. Because these host-response tests have been designed using data from Western Europe and North America, they fail to account for the types of infections that are prevalent in low- and middle-income countries. In particular, they have trouble distinguishing the more subtle differences between intracellular bacterial infections and viral infections. In developing countries, common bacterial infections like typhus and tuberculosis are caused by intracellular bacteria, which replicate inside human cells, as do viruses.

To develop a diagnostic test that can separate both types of bacterial infections from viral infections, the Stanford Medicine scientists used publicly available gene expression data from 35 countries. These included 4,754 samples from people of various ages, sexes and races with known infections. The diversity of patients, infections and types of data is more representative of the real world, according to the researchers. Using machine learning and half of these samples, they identified eight genes that are expressed differently in bacterial versus viral infections. They validated their eight-gene test on the remaining samples and more than 300 new samples collected from Nepal and Laos.

They found that these eight genes could distinguish intracellular and extracellular bacterial infections from viral infections with high accuracy, achieving 90% sensitivity and 90% specificity. It is the first diagnostic test to meet (and exceed) the standards proposed by the World Health Organization and the Foundation for Innovative New Diagnostics. The researchers hope that the new diagnostic test can eventually be translated into a point-of-care test and adopted by doctors in both developed and developing countries, as it requires only a blood sample and can be performed in 30 to 45 minutes. The team has applied for a patent on the test.

“Accurately diagnosing whether a patient has a bacterial or viral infection is one of the biggest global health challenges,” said Purvesh Khatri, PhD, associate professor of medicine and biomedical data science, and the senior author. “We’ve shown that this eight-gene signature has higher accuracy and more generalizability for distinguishing bacterial and viral infections, irrespective of whether they are intracellular or extracellular, whether a patient is in a developed or developing country, a man or a woman, an infant or an 80-year-old.”

Related Links:
Stanford Medicine

Gold Supplier
Vaginosis Test
VAGINAL PANEL REALTIME PCR KIT
New
Rapid H. Pylori Antibody Test
Reveal HP
New
Semi-Auto Microfluidic Immunofluorescent Analyzer
mLabs Smart
New
HbA1c Test
LumiraDx HbA1c Test

Print article
MEDLAB - INFORMA

Channels

Molecular Diagnostics

view channel
Image: A novel research study moves the needle on predicting sudden cardiac arrest (Photo courtesy of Pexels)

Newly Identified Protein Biomarkers in Blood Predict Sudden Cardiac Arrest Before it Strikes

Sudden cardiac arrest, or the sudden loss of heartbeat, is a life-threatening heart condition and often fatal. Despite providing an organized emergency medical response, less than 10% of individuals having... Read more

Immunology

view channel
Image: Histopathology of Langerhans cell histiocytosis: The variation in nuclear contours of these cells is evident in this lesion. Classic `kidney bean` nuclei of Langerhans cells with a central groove are present (Photo courtesy of John Lazarchick, MD)

Cooperativity Between Myeloid Lineages Promotes Langerhans Cell Histiocytosis Pathology

Langerhans cell histiocytosis (LCH) is an inflammatory myeloid neoplasia seen in children and adults who present with lesions composed of pathologic variants of myeloid cells that share certain phenotypic... Read more

Technology

view channel
Image: Flexible copper sensor made cheaply from ordinary materials (Photo courtesy of University of São Paulo)

Low-Cost Portable Sensor Detects Heavy Metals in Sweat

Heavy metals like lead and cadmium can be found in batteries, cosmetics, food and many other things that have become a part of daily life. However, they become toxic if they accumulate in the human body... Read more
Copyright © 2000-2023 Globetech Media. All rights reserved.